Optical wavelength dispersion device and manufacturing method therefor

ABSTRACT

An optical wavelength dispersion device and manufacturing method therefor are disclosed, wherein the optical wavelength dispersion device includes a waveguide unit and a reflector, wherein the waveguide unit has a first substrate, an input unit, a grating and a second substrate. The input unit is formed on the first substrate and having a slit for receiving an optical signal, a grating is formed on the first substrate for producing an output beam once the optical signal is dispersed, the second substrate is located on the input unit and the grating, and forms a waveguide space with the first substrate, the reflector is located outside of the waveguide unit, and is used for change emitting angle of the output beam.

CROSS REFERENCE OF RELATED APPLICATION

This is divisional application that claims the benefit of priority under35U.S.C. § 120 to a non-provisional application, application Ser. No.15/885,768, filed Jan. 31, 2018, which is incorporated herewith byreference in its entity.

NOTICE OF COPYRIGHT

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to any reproduction by anyone of the patent disclosure, as itappears in the United States Patent and Trademark Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

BACKGROUND OF THE PRESENT INVENTION Field of Invention

The present invention generally relates to a wavelength dispersiondevice and a manufacturing method for producing the same, moreparticularly to an optical wavelength dispersion device capable ofreducing the size and improving the degree of precise of the opticalwavelength dispersion device.

Description of Related Arts

Conventional spectrometers generally use prism, grating or interferenceto realize dispersion effect, however, the overall size and theresolution ability of a spectrometer needs to be compromised with eachother. Therefore, a conventional high resolution spectrometer is moreexpensive due to the sizable and complicated optical system.

In order to reduce the size of a spectrometer, LIGA (stands forLithography, Electroplating, and Molding) is applied, which is amicro-manufacturing program combining lithography, electroplating, andmolding, so as to enable a micro-structure to have higher degree ofprecision during manufacturing, moreover, to produce a micro-structurehaving a height between hundreds and thousands of micrometer. Due to thestructure of grating which needs to have small spacing, the yield ofLIGA during the molding process and the degree of precision areinsufficient for manufacturing vertical gratings.

Hence, how to realize an optical wavelength dispersion device that iscapable of reducing the size and improving the degree of precise iscertainly a meaningful issue to resolve.

SUMMARY OF THE PRESENT INVENTION

An object of the present invention is to disclose a wavelengthdispersion device and a manufacturing method for producing the same,which aim to serve a purpose of reducing the size and improving thedegree of precise of the optical wavelength dispersion device.

In order to achieve the objective of the present invention, an opticalwavelength dispersion device is provided, which comprises:

-   -   a waveguide unit and a reflector, wherein the waveguide unit has        a first substrate, an input unit, a grating and a second        substrate. The input unit is formed on the first substrate and        having a slit for receiving an optical signal, a grating is        formed on the first substrate for producing an output beam once        the optical signal is dispersed, the second substrate is located        on the input unit and the grating, and forms a waveguide space        with the first substrate, the reflector is located outside of        the waveguide unit, and is used for change emitting angle of the        output beam; wherein the input unit and the grating are formed        by exposing a photoresist layer under a high energy light        source.

According to one embodiment of the present invention, the grating has aconcave, convex or planar profile, and with a surface appearing in acontinuous laminar type, a saw-tooth type, a blaze type, a sinusoidaltype, or a combination of the above.

According to one embodiment of the present invention, the firstsubstrate and the second substrate may be selected from any ofsemiconductor substrates, glass substrates, metal substrates or plasticsubstrates.

According to one embodiment of the present invention, the high energylight source is selected from any of X-ray, soft X-ray or extremeultraviolet (EUV).

In order to achieve the objective of the present invention, amanufacturing method for producing an optical wavelength dispersiondevice is also provided, which includes the following steps: providing afirst substrate; forming a photoresist layer on the first substrate;exposing the photoresist layer through a high energy light source maskby using a high energy light source, and the high energy light sourcehas its wavelength ranging from 0.01 nm to 100 nm; developing thephotoresist layer so as to form an input unit having a slit and agrating; using a second substrate to cover the input unit and thegrating, thereby forming a waveguide unit; and allocating a reflectoroutside of the waveguide unit.

According to one embodiment of the present invention, the thickness ofthe photoresist layer is between 10 μm and 1000 μm.

According to one embodiment of the present invention, the high energylight source mask includes a third substrate, a metal layer formed onthe third substrate, a plurality of metal patterns formed on the top ofthe metal layer, and a silicon layer formed on the bottom of the thirdsubstrate.

According to one embodiment of the present invention, the thirdsubstrate of the high energy light source mask may be made of Si₃N₄ orSiC, and the thickness is between 1 μm and 5 μm.

According to one embodiment of the present invention, the metal layer isa Ti layer with a thickness ranging from 10 nm to 200 nm, and theplurality of metal patterns are all Au patterns with a thickness rangingfrom 1 μm to 10 μm.

According to one embodiment of the present invention, the method furtherincludes a step to coat a high reflectivity coating layer onto the firstsubstrate, the second substrate, the input unit and the grating.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention willbecome apparent from the following description of the accompanyingdrawings, which disclose several embodiments of the present invention.It is to be understood that the drawings are to be used for purposes ofillustration only, and not as a definition of the invention.

FIG. 1 (a) illustrates a preferred embodiment of the disclosed opticalwavelength dispersion device.

FIG. 1 (b) illustrates an explosion drawing of the aforementionedpreferred embodiment of the disclosed optical wavelength dispersiondevice.

FIG. 1 (c) illustrates the aforementioned preferred embodiment of thedisclosed optical wavelength dispersion device.

FIG. 2 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

FIG. 3 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

FIG. 4 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

FIG. 5 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

FIG. 6 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

FIG. 7 illustrates a step in a preferred embodiment of the disclosedmanufacturing method for producing the optical wavelength dispersiondevice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following description is disclosed to enable any person skilled inthe art to make and use the present invention. Preferred embodiments areprovided in the following description only as examples and modificationswill be apparent to those skilled in the art. The general principlesdefined in the following description would be applied to otherembodiments, alternatives, modifications, equivalents, and applicationswithout departing from the spirit and scope of the present invention.

For those skilled in the art, it is understood that terms disclosed inthe present invention, such as “horizontal”, “vertical”, “up”, “down”,“front”, “rear”, “left”, “right”, “upright”, “level”, “top”, “bottom”,“inside”, “outside”, and etc., are to indicate the directional positionor location based on the disclosed figures, which are merely used todescribe the present invention and simplify the description withoutindicating or implying a specific position or location of an apparatusor component, or a specific positional structure or operation.Therefore, the terms are not to be understood as limitations to thepresent invention.

It is understandable that, “one” is interpreted as “at least one” or“one or more than one”, even though one embodiment disclosed in thepresent invention uses “one” indicating the number of a component isone, it is possible for another embodiment to have “at least one” or“one or more than one” for the number of a component. Therefore, “one”is not to be interpreted as a limitation for number.

Although some words has been used in the specification and subsequentclaims to refer to particular components, person having ordinary skillin the art will appreciates that manufacturers may use different termsto refer to a component. The specification and claims are not to bedifferences in the names as a way to distinguish between the components,but with differences in the function of the component as a criterion todistinguish. As mentioned throughout the specification and claims, inwhich the “include, has, comprise, and with” are an open-ended term,they should be interpreted as “including but not limited to”.

FIG. 1(a)-1(c) illustrate diagrams of the preferred embodiment for theoptical wavelength dispersion device disclosed in the present invention,which show: an optical wavelength dispersion device 10 is made of awaveguide unit 11 and a reflector 12. The waveguide unit 11 has a firstsubstrate 111, an input unit 112, a grating 113 and a second substrate(as shown in FIG. 1(b)). The input unit 112 is formed on the firstsubstrate 111 and having a slit 114 for receiving an optical signal,wherein the slit 114 has a width ranged between 5 μm and 500 μm. Thegrating 113 is formed on the first substrate 111, which generates andoutputs a first beam (defocused and focused beam) based on the opticalsignal, thereby conducting dispersion, and having the incident arrangedat the reflector 12 outside of the waveguide unit 11. The grating 113has a concave, convex or planar profile, and with a surface appearing ina continuous laminar type, a saw-tooth type, a blaze type, a sinusoidaltype, or a combination of the above. Generally speaking, the grating 113is used for increasing the diffraction efficiency of specifieddiffraction hierarchy, and an appropriate wavelength of the opticalsignal is from 200 nm to 2000 nm. The reflector 12 is used foroutputting the first beam (defocused and focused beam) from the grating113, and is able to change emitting angle of the first beam.

Image sensor 151 (as shown in FIG. 1(b)) is used for receiving the firstbeam from the reflector 12 for subsequent processes. The secondsubstrate 117 is covered on the input unit 112 and the grating 113;therefore, space constituted between the first substrate 111 and secondsubstrate 117 can be viewed as a waveguide unit 11, which is used forreceiving and transmitting optical signals. In addition, the input unit112 and the grating 113 are formed by exposing a photoresist layer undera high energy light source. The high energy light source may be selectedfrom any of X-ray, soft X-ray or extreme ultraviolet (EUV), wherein theX-ray has its wavelength ranging from 0.01 nm to 1 nm; the soft X-rayhas its wavelength ranging from 0.1 nm to 10 nm; the EUV has itswavelength ranging from 10 nm to 120 nm. The first substrate 111 and thesecond substrate 117 may be selected from any of semiconductorsubstrates, glass substrates, metal substrates or plastic substrates.Notably, due to the surface roughness limitation in opticaltelecommunications and local optical communications, the wavelength with0.1 nm to 1 nm of the high energy light source is better than that with1 nm to 100 nm.

Once exposed under the high energy light source, the pitch betweenadjacent peaks of the grating 113 is about 3 m, and the surfaceroughness of the grating 113 is from 5 nm to 10 nm. Thus, the grating113 is suitable for being used in both optical telecommunications andlocal optical communications.

Furthermore, when the reflector 12 is formed in one-piece by tilting anangle onto the first substrate, the reflecting surface of the reflector12 will be too rough due to a rotating exposure to meet the need of anoptical system, in terms of current semiconductor manufacturingtechnique. Therefore, one preferred embodiment in the present inventionhas the reflector 12 allocated outside of the waveguide unit by anothersemiconductor manufacturing process, thereby increasing the degree ofprecision for wavelength dispersion.

As disclosed in the aforementioned embodiment, the reflector 12 is usedfor changing output angle of the first beam from the grating 113, hence,the image sensor 151 can be placed in any direction and location(particularly above or below) of the optical wavelength dispersiondevice based on user's requirements, thereby reducing the overall size.

The optical wavelength dispersion device 10 further includes aconfiguration that wraps up the waveguide unit 11 and the reflector 12by using an outer casing 13 and a covering plate 14. Having protected bythe outer casing 13 and the covering plate 14, the waveguide unit 11 andthe reflector 12 avoid direct contact with external force, therebymaintaining stability of the overall structure. When optical signalenters into the waveguide unit 11 through the slit 114 of the input unit16 (usually an optical fiber cable), the process of dispersion begins.

Moreover, since the reflector 12 changes emitting angle of the firstbeam, the covering plate 14 is arranged with an opening 141 with respectto the reflector 12, thereby enabling the first beam to output. In thepreferred embodiment of the present invention, the covering plate 14 isallocated with an IC carrier 15 (IC: integrated circuit), and the imagesensor 151 is arranged on the IC carrier 15 in corresponding to theposition of the opening 141, so as to receive the first beam forsubsequent analyses. To combine the image sensor 151 with the disclosedoptical wavelength dispersion device, it reduces further the size ofoverall system.

FIG. 2 to 7 illustrate the steps of manufacturing method for producingthe optical wavelength dispersion device. To manufacture the opticalwavelength dispersion device, steps are shown as illustrated in FIG. 2to 7 : firstly, providing a first substrate 111, and forming aphotoresist layer 115 with a thickness ranging from 10 nm to 1000 nmm onthe first substrate 111, wherein part of elements in the opticalwavelength device 10 are to be formed through the photoresist layer 115.The photoresist layer 115 is made of SU-8 (SU-8 is an epoxy-basednegative photoresist) or PMMA (PMMA is shorthand for poly (methylmethacrylate)). Secondly, the photoresist layer 115 is exposed through ahigh energy light source mask 20 under a high energy light source 30(such as X-ray, soft X-ray or EUV); wherein the high energy light sourcemask 20 includes a third substrate 201 made of Si₃N₄ or SiC, and itsthickness is between 1 μm and 5 μm; the high energy light source mask 20further includes a Ti layer 204 (metal layer) formed on the thirdsubstrate 201 with a thickness from 10 nm to 200 nm, a plurality of Aupatterns 203 (metal patterns) formed on the Ti layer 204, and a siliconlayer 202 formed on the bottom of the third substrate 201. Part of thehigh energy light source 30 will be shielded by the plurality of Aupatterns 203 with thickness from 1 nm to 10 nm, and the Au patterns 203on the high energy light source 30 will be transferred onto thephotoresist layer 115 under an exposure of high energy light source.

For example, having exposed by the high energy light source, the exposedarea on the photoresist layer 115 will be developed. Once developed, aninput unit 112 with a slit and a grating 113 will be formed on thephotoresist layer 115. Additionally, in order to increase input unit 112and grating 113, hard baking will be performed on the input unit 112 andthe grating 113 under temperature from 100° C. to 200° C.

To reinforce the ratio of reflection of the waveguide unit 11 having thefirst substrate 111, the input unit 112 and the grating 113, a highreflectivity coating layer 116 (Au or Al) can be coated onto the firstsubstrate 111, the input unit 112 and the grating 113.

Finally, covering up the input unit 112 and the grating 113 with thesecond substrate 117 that has been coated with a high reflectivitycoating layer 116 (Au or Al). Therefore, a space between the firstsubstrate 111 and the second substrate 117 as shown in FIG. 7 can beviewed as a waveguide space. Then, the reflector 12 is arranged outsideof the waveguide unit 11 for changing the output angle of the first beamfrom the grating 113.

Furthermore, a plurality of first connecting units (not shown) is formedon the first substrate 111, which is used as a connected bridge with thesecond substrate 117. By the connection of the plurality of connectingunits (not shown), the structural stability of the optical wavelengthdispersion device can be improved accordingly.

There have thus been shown and described an optical wavelengthdispersion device and a manufacturing method for producing the same.Many changes, modifications, variations and other uses and applicationsof the subject invention will, however, become apparent to those skilledin the art after considering this specification and the accompanyingdrawings which disclose the preferred embodiments thereof. All suchchanges, modifications, variations and other uses and applications whichdo not depart from the spirit and scope of the invention are deemed tobe covered by the invention.

Although some words has been used in the specification and subsequentclaims to refer to particular components, person having ordinary skillin the art will appreciates that manufacturers may use different termsto refer to a component. The specification and claims are not to bedifferences in the names as a way to distinguish between the components,but with differences in the function of the component as a criterion todistinguish.

Preferred embodiments are provided only as examples without limiting thescope of the present invention, and modifications will be apparent tothose skilled in the art. The purpose of the present invention has beencompleted and served effectively. The functions and general principlesdefined in the present invention would be applied to other embodiments,alternatives, modifications, equivalents, and applications withoutdeparting from the spirit and scope of the present invention.

What is claimed is:
 1. A manufacturing method of optical wavelengthdispersion device, comprising steps of: (a) providing a first substrate;(b) forming a photoresist layer with a thickness ranging from 10 μm to1000 μm on the first substrate; (c) forming an input unit and a gratingon the first substrate by exposing the photoresist layer under a highenergy light source selected from a group consisting of X-ray having awavelength ranging from 0.01 nm to 1 nm, soft X-ray having a wavelengthranging from 0.1 nm to 10 nm and ultraviolet (EUV) having a wavelengthranging from 10 nm to 120 nm, wherein the input unit has a slit having awidth ranged between 5 μm and 500 μm, wherein the grating is used forreceiving an optical signal having a wavelength ranged from 200 nm to2000 nm and conducting dispersion, wherein the grating has a surface,selected from a group consisting of a continuous laminar type surface, asaw-tooth type surface, a blaze type surface, a sinusoidal type surface,and a combination thereof, for increasing a diffraction efficiency ofspecified diffraction hierarchy; (d) covering the input unit and thegrating with a second substrate to constitute a waveguide space betweenthe first substrate and the second substrate for receiving andtransmitting the optical signal to form a waveguide unit for generatingand outputting a first beam which is a defocused and focused beam basedon the optical signal; and (e) allocating a reflector outside thewaveguide unit while tilting an angle onto the first substrate foroutputting the first beam from the grating, changing an emitting angleof the first beam, changing an output angle of the first beam from thegrating, so as to increase a degree of precision for wavelengthdispersion to form an optical wavelength dispersion device such that animage sensor, adapted for receiving the first beam from the reflector,is capable of being placed in any direction and location above or belowthe optical wavelength dispersion device.
 2. The manufacturing method,as recited in claim 1, further comprising a step of wrapping thewaveguide unit and the reflector with an outer casing and a coveringplate in such a manner that the optical signal from an input unit isable to enter into the waveguide space of the waveguide unit through theslit, wherein the covering plate has an opening positioned with respectto the reflector to enable the first beam to output therethrough and incorresponding to the image sensor arranged on an IC carrier.
 3. Themanufacturing method, as recited in claim 1, wherein the photoresistlayer is exposed through a high energy light source mask under the highenergy light source, wherein the high energy light source mask includesa third substrate, made of a material selected from a group consistingof Si₃N₄ and SiC, having a thickness ranged between 1 μm and 5 μm, a Tilayer formed on the third substrate and having a thickness ranged from10 nm to 200 nm, a plurality of Au patterns formed on the Ti layer andhaving a thickness ranged from 1 nm to 10 nm, and a silicon layer formedon a bottom of the third substrate, wherein the photoresist layer isexposed by shielding a part of the high energy light source by theplurality of Au pattern and transferring the high energy light sourceonto the photoresist layer under an exposure of the high energy lightsource, wherein once exposed under the high energy light source, a pitchbetween adjacent peaks of the grating is preferred to be 3 μm and asurface roughness of the grating is ranged from 5 nm to 10 nm.
 4. Themanufacturing method, as recited in claim 2, wherein the photoresistlayer is exposed through a high energy light source mask under the highenergy light source, wherein the high energy light source mask includesa third substrate, made of a material selected from a group consistingof Si₃N₄ and SiC, having a thickness ranged between 1 μm and 5 μm, a Tilayer formed on the third substrate and having a thickness ranged from10 nm to 200 nm, a plurality of Au patterns formed on the Ti layer andhaving a thickness ranged from 1 nm to 10 nm, and a silicon layer formedon a bottom of the third substrate, wherein the photoresist layer isexposed by shielding a part of the high energy light source by theplurality of Au pattern and transferring the high energy light sourceonto the photoresist layer under an exposure of the high energy lightsource, wherein once exposed under the high energy light source, a pitchbetween adjacent peaks of the grating is preferred to be 3 μm and asurface roughness of the grating is ranged from 5 nm to 10 nm.
 5. Themanufacturing method, as recited in claim 1, after the step (c), furthercomprising a step of coating the first substrate, the input unit and thegrating with a high reflectivity coating layer made of a materialselected from a group consisting of Au and Al.
 6. The manufacturingmethod, as recited in claim 2, after the step (c), further comprising astep of coating the first substrate, the input unit and the grating witha high reflectivity coating layer made of a material selected from agroup consisting of Au and Al.
 7. The manufacturing method, as recitedin claim 3, after the step (c), further comprising a step of coating thefirst substrate, the input unit and the grating with a high reflectivitycoating layer made of a material selected from a group consisting of Auand Al.
 8. The manufacturing method, as recited in claim 4, after thestep (c), further comprising a step of coating the first substrate, theinput unit and the grating with a high reflectivity coating layer madeof a material selected from a group consisting of Au and Al.
 9. Themanufacturing method, as recited in claim 3, wherein the photoresistlayer is made of a material selected from a group consisting of SU-8 andPMMA.
 10. The manufacturing method, as recited in claim 4, wherein saidphotoresist layer is made of a material selected from a group consistingof SU-8 the PMMA.
 11. The manufacturing method, as recited in claim 7,wherein the photoresist layer is made of a material selected from agroup consisting of SU-8 and PMMA.
 12. The manufacturing method, asrecited in claim 8, wherein the photoresist layer is made of a materialselected from a group consisting of SU-8 and PMMA.
 13. The manufacturingmethod, as recited in claim 1, wherein each of the first substrate andsecond substrate is selected from a group consisting of semiconductorsubstrate, glass substrate, metal substrate, and plastic substrate. 14.The manufacturing method, as recited in claim 2, wherein each of thefirst substrate and second substrate is selected from a group consistingof semiconductor substrate, glass substrate, metal substrate, andplastic substrate.
 15. The manufacturing method, as recited in claim 3,wherein each of the first substrate and second substrate is selectedfrom a group consisting of semiconductor substrate, glass substrate,metal substrate, and plastic substrate.
 16. The manufacturing method, asrecited in claim 4, wherein each of the first substrate and secondsubstrate is selected from a group consisting of semiconductorsubstrate, glass substrate, metal substrate, and plastic substrate. 17.The manufacturing method, as recited in claim 7, wherein each of thefirst substrate and second substrate is selected from a group consistingof semiconductor substrate, glass substrate, metal substrate, andplastic substrate.
 18. The manufacturing method, as recited in claim 8,wherein each of the first substrate and second substrate is selectedfrom a group consisting of semiconductor substrate, glass substrate,metal substrate, and plastic substrate.
 19. The manufacturing method, asrecited in claim 11, wherein each of the first substrate and secondsubstrate is selected from a group consisting of semiconductorsubstrate, glass substrate, metal substrate, and plastic substrate. 20.The manufacturing method, as recited in claim 12, wherein each of thefirst substrate and second substrate is selected from a group consistingof semiconductor substrate, glass substrate, metal substrate, andplastic substrate.